Electrically driven pump and method for manufacturing the same

An electrically driven pump, comprising a first housing, a second housing, a partition, a stator assembly, a circuit board and a rotor assembly, wherein the electrically driven pump comprises a pump chamber, the pump chamber comprises a space defined by the first housing and the second housing, the pump chamber is divided, by the partition, into a dry chamber and a wet chamber, the rotor assembly is arranged in the wet chamber, and the stator assembly and the circuit board are arranged in the dry chamber, wherein:

• the rotor assembly comprises an impeller, a rotor and a shaft sleeve assembly, and each of the impeller, the rotor and the shaft sleeve assembly is separately formed, the shaft sleeve assembly comprises a shaft sleeve, the impeller is arranged on one end of the shaft sleeve, and the rotor is arranged on another end of the shaft sleeve;
• and
• the rotor comprises a permanent magnet, a rotor core and a shield, the permanent magnet is fixed to the rotor core, the rotor core is fixed to the shaft sleeve, the shield and the shaft sleeve are both made of metal, welded together to form a closed accommodating portion between the shield and an outer circumferential surface of the shaft sleeve, and the permanent magnet is fixedly arranged in the accommodating portion;
• wherein the shield comprises an upper end plate, a lower end plate and a shield sleeve, all of which are made of stainless steel, and the upper end plate, the lower end plate, the shield sleeve and the outer circumferential surface of the shaft sleeve are fixedly connected by welding to allow the rotor core and the permanent magnet to be fixed in the accommodating portion formed by the shield and the shaft sleeve,
• the upper end plate comprises a first protrusion, a second protrusion, and a flat plate arranged between the first protrusion and the second protrusion,
• the upper end plate comprises a center hole, and the first protrusion is arranged around the center hole, and the upper end plate is sleeved on the outer circumferential surface of the shaft sleeve through the center hole, and the second protrusion is formed on an outer edge of the upper end plate, the upper end plate is in contact with the outer circumferential surface of the shaft sleeve via the first protrusion,
• the second protrusion is formed on an outer edge of the upper end plate and the second protrusion is in contact with an inner circumferential surface or an outer circumferential surface of the shield sleeve,
• wherein the shaft sleeve assembly further comprises bearings, the bearings comprise a first bearing and a second bearing, a first step portion and a second step portion are formed on the shaft sleeve, the first step portion is arranged to be close to the impeller, the second step portion is arranged to be close to the rotor, the first step portion comprises a first step surface and a first side wall, the second step portion comprises a second step surface and a second side wall, the first bearing is mounted on the first step portion, and the second bearing is mounted on the second step portion,
• wherein the shaft sleeve assembly further comprises, one buffer or two buffers;
• if there is one buffer, the buffer is arranged between the first bearing and the shaft sleeve, or between the second bearing and the shaft sleeve;
• or if there are two buffers, one buffer is arranged between the first bearing and the shaft sleeve, and the other buffer is arranged between the second bearing and the shaft sleeve;
• each buffer of the one buffer or two buffers has a gap structure, a protrusion structure formed on an inner peripheral surface, and the protrusion structure is in contact with an outer circumferential surface of the bearings, and the outer peripheral surface of the buffer is in contact with the shaft sleeve.

An electrically driven pump, comprising a first housing, a second housing, a partition, a stator assembly, a circuit board and a rotor assembly, wherein the electrically driven pump comprises a pump chamber, the pump chamber comprises a space defined by the first housing and the second housing, the pump chamber is divided, by the partition, into a dry chamber and a wet chamber, the rotor assembly is arranged in the wet chamber, and the stator assembly and the circuit board are arranged in the dry chamber, wherein:

• the rotor assembly comprises an impeller, a rotor and a shaft sleeve assembly, and each of the impeller, the rotor and the shaft sleeve assembly is separately formed, the shaft sleeve assembly comprises a shaft sleeve, the impeller is arranged on one end of the shaft sleeve, and the rotor is arranged on another end of the shaft sleeve;
• and
• the rotor comprises a permanent magnet, a rotor core and a shield, the permanent magnet is fixed to the rotor core, the rotor core is fixed to the shaft sleeve, the shield and the shaft sleeve are both made of metal, welded together to form a closed accommodating portion between the shield and an outer circumferential surface of the shaft sleeve, and the permanent magnet is fixedly arranged in the accommodating portion;
• wherein the shield comprises an upper end plate, a lower end plate and a shield sleeve, all of which are made of stainless steel, and the upper end plate, the lower end plate, the shield sleeve and the outer circumferential surface of the shaft sleeve are fixedly connected by welding to allow the rotor core and the permanent magnet to be fixed in the accommodating portion formed by the shield and the shaft sleeve,
• the upper end plate comprises a first protrusion, a second protrusion, and a flat plate arranged between the first protrusion and the second protrusion,
• the upper end plate comprises a center hole, and the first protrusion is arranged around the center hole, and the upper end plate is sleeved on the outer circumferential surface of the shaft sleeve through the center hole, and the second protrusion is formed on an outer edge of the upper end plate, the upper end plate is in contact with the outer circumferential surface of the shaft sleeve via the first protrusion,
• the second protrusion is formed on an outer edge of the upper end plate and the second protrusion is in contact with an inner circumferential surface or an outer circumferential surface of the shield sleeve,
• wherein the rotor assembly further comprises a balancing sleeve, the balancing sleeve is made of a metal material, the balancing sleeve is sleeved on the shaft sleeve, and the balancing sleeve is arranged between the impeller and the rotor;
• and an outer step surface is formed on an outer circumferential surface of the shaft sleeve, and the balancing sleeve has one end surface abutting against the outer step surface and another end surface functioning as a positioning portion in axially mounting the impeller.